Looking for more information about the optional install of coordinate systems. The What's new document for Desktop 10.5 document says this:
ArcGIS Coordinate Systems Data—Contains the data files required for the GEOCON transformation method and vertical transformation files for the United States (VERTCON and GEOID12B) and the world (EGM2008).
but I'm not seeing any discussion in the help documents for 10.5. I'm thinking some of our users may have need for this but I am having trouble finding more information. Is there an article, blog post, Esri UC session, or anything like that available that I can point my users to?